correct usage messages

Notes:
Sat Jul 23 10:05:02 EDT 2005 rsc
    made a usage() function too.


Reference: /n/sources/patch/applied/listen-usage
Date: Fri Jul 22 23:25:19 CES 2005
Reviewed-by: rsc

--- /sys/src/cmd/aux/listen.c	Fri Jul 22 23:25:06 2005
+++ /sys/src/cmd/aux/listen.c	Fri Jul 22 23:25:03 2005
@@ -71,7 +71,7 @@
 		namespace = ARGF();
 		break;
 	default:
-		error("usage: listen [-d servdir] [-t trustdir] [proto]");
+		error("usage: listen [-q] [-n namespace] [-d servdir] [-t trustdir] [proto [name]]");
 	}ARGEND;
 
 	if(!servdir && !trustdir)
@@ -89,7 +89,7 @@
 	case 0:
 		break;
 	default:
-		error("usage: listen [-d servdir] [-t trustdir] [proto]");
+		error("usage: listen [-q] [-n namespace] [-d servdir] [-t trustdir] [proto [name]]");
 	}
 
 	syslog(0, listenlog, "started");